1. A company fine-tuned a GPT-4o-mini model on 3,000 labeled examples to perform sentiment classification. After deployment, the model's accuracy on new production data drops significantly compared to validation accuracy. They have not changed the prompt or fine-tuning configuration. Which THREE factors are the most likely contributors to this degradation? (Choose THREE)
- A. Distribution shift: production data has different vocabulary or topics than the fine-tuning dataset✓ Correct
- B. The fine-tuning learning rate was too low, causing the model to underfit the training data
- C. Overfitting to the fine-tuning dataset due to insufficient training data diversity or too many epochs✓ Correct
- D. The base model was updated by Microsoft after fine-tuning, and the fine-tuned adapter is no longer compatible
- E. The production prompts differ from the prompt format used during fine-tuning, breaking the learned pattern✓ Correct
- F. The `max_tokens` parameter in the deployment is set too low, truncating output
Explanation
Distribution shift (A) is a primary cause of post-deployment accuracy drops when production data differs from training data. Overfitting (C) on small datasets causes the model to memorize training examples and generalize poorly. Prompt format mismatch (E) is a common fine-tuning pitfall—the model learns to respond to the exact prompt structure used during training, and deviations at inference time degrade performance. A low learning rate causing underfitting (B) would have shown poor validation accuracy during fine-tuning, which is not described here. Azure OpenAI fine-tuned model adapters are tied to a specific base model snapshot and are not silently invalidated by base model updates (D)—this is managed separately. A low `max_tokens` (F) would truncate completions but for a classification task returning a short label, this is unlikely to cause the observed accuracy drop.